Spontaneous activity is a common feature in the developing mammalian nervous system. During the development of the visual system prior to vision, neighboring retinal ganglion cells, the output neurons of the retina, fire spontaneous correlated bursts of action potentials followed by a period of silence lasting roughly 1 minute. This activity that propagates across the retina is termed "retinal waves." Retinal waves are required for the refinement of appropriate synaptic connections of ganglion cells to visual centers of the brain. How is spontaneous activity generated on the order of once per minute? We will investigate this question using a combination of molecular biology, imaging, and electrophysiology to study the cellular mechanisms that underlie the properties of this periodic spontaneous activity. Specifically, we will investigate the role of dynamic levels of cAMP in regulating a slow afterhyperpolarizing conductance that determines wave frequency. The proposed experiments will help us understand the basis for activity that is necessary for the development of the brain. Knowledge gained from this research may help us explain disorders of the nervous system and could provide a foundation for means of repairing the injured brain.